Inflammation Research

, Volume 63, Issue 7, pp 591–596

Effect of nitric oxide on microRNA-155 expression in human hepatic epithelial cells

Original Research Paper

DOI: 10.1007/s00011-014-0730-8

Cite this article as:
Yuhas, Y., Berent, E. & Ashkenazi, S. Inflamm. Res. (2014) 63: 591. doi:10.1007/s00011-014-0730-8

Abstract

Objective

Nitric oxide (NO) is a signaling molecule and regulator of immunity and inflammation. MicroRNAs (miRNAs) regulate gene transcription and are involved in inflammatory processes and cancer. This study sought to determine if NO activity affects miRNA expression.

Methods

Human liver epithelial (HepG2) cells were treated with the NO-releasing S-nitroso-N-acetylpenicillamine (SNAP) 100 μM for 4 h and subjected to microarray analysis. To examine the underlying mechanisms, cells were exposed to cGMP analog 8-bromo-cGMP, protein kinase inhibitor Rp-*-Br-PET-cGMPS (Rp-PET), or nitric synthase inhibitor l-NAME and evaluated with RT-PCR.

Results

MiR-155 was the only miRNA of the 887 arrayed that showed a change in expression after SNAP treatment. Incubation of the cells with 8-bromo-cGMP increased miR-155 expression 4.0 ± 0.7-fold (p < 0.05); Rp-PET before SNAP had a dual, concentration-dependent effect. SNAP treatment induced a 3.1 ± 0.7-fold change in miRNA-155 expression, Rp-PET 25 μM, a 7.3 ± 2.2-fold change, and Rp-PET 100 μM, a 0.79 ± 0.09-fold change (SNAP vs SNAP + Rp-PET, p < 0.05). In unstimulated cells, Rp-PET or l-NAME treatment increased miR-155 expression by 3.5 ± 0.7-fold and 5.6 ± 2.2-fold, respectively (p < 0.05).

Conclusion

In HepG2 cells, exogenous NO increases miR-155 expression, but endogenous basal NO inhibits it. Both effects are mediated via cGMP/PKG signaling. The upregulation of miR-155 by NO provides a new link between NO, inflammation, and cancer.

Keywords

Nitric oxideMicroRNAsMiR-155Inflammation

Abbreviations

NO

Nitric oxide

miRNA

MicroRNA

NOS

Nitric oxide synthase

eNOS

Endothelial NOS

iNOS

Inducible NOS

HepG2

Hepatic epithelial (cells)

IL-8

Interleukin-8

SNAP

S-nitroso-N-acetylpenicillamine

SNP

Sodium nitroprusside

sGC

Soluble guanylyl cyclase

cGMP

Cyclic guanosine monophosphate

PKG

Protein kinase G

Rp-PET

Rp-8-Bromo-beta-phenyl-1,N2-ethenoguanosine 3′5′-cyclic monophosphorothioate sodium salt (Rp-*-Br-PET-cGMPS)

l-NAME

NG-nitro-l-arginine methyl ester

Poly I:C

Polyriboinosinic-polyribocytidylic acid

MAPK

Mitogen-activated protein kinase

Copyright information

© Springer Basel 2014

Authors and Affiliations

  1. 1.Infectious Diseases Research LaboratoryFelsenstein Medical Research CenterPetach TikvaIsrael
  2. 2.Department of Pediatrics ASchneider Children’s Medical CenterPetach TikvaIsrael
  3. 3.Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael